What's a Good ACoS on Amazon? The Honest Answer Most Articles Won't Give You

The Short Answer: What’s a Good ACoS on Amazon?

A good ACoS is one that is lower than your break-even ACoS (the point at which your ad spend eats into your contribution margin, leaving you with neither profit nor loss).

This number will vary per product, and you can only know the answer based on your own unit economics. A quick formula is contribution margin divided by selling price.

Category benchmarks are the starting reference, not the target. Two products that come from the same category can have two different answers, depending on your commercial objective.

In this guide, we will cover the break-even formula and an example of how it works; you will see how your commercial goal impacts the target and why ACoS is the wrong metric to track and which one to replace it with.

ACoS Defined: What It Actually Measures (And What It Doesn’t)

ACoS (Advertising Cost of Sales) = ad spend ÷ ad-attributed revenue.

For example, if you have spent $200 on ads and those ads have resulted in $1,000 in attributed sales, your ACoS would be 20%. It gives you the efficiency of your ad spend versus the revenue that came through a paid click and nothing else.

But what ACoS doesn’t measure is the organic revenue.

While a 15% ACoS might look good on paper, if organic sales decline slowly, it means that the ads are compensating and that your entire business is becoming more ad-dependent.

ACoS also doesn’t tell you if that sale was profitable. A 15% ACoS on a product with a 12% contribution margin is losing money on every single order. The metric looks fine. The business outcome isn't.
ROAS is the same picture, but inverted.

ROAS (Return on Ad Spend) = revenue ÷ ad spend

25% ACoS is the same as a 4x ROAS. Both metrics come up often in conversations about Amazon advertising, but they are just looking at the same relationship from different sides: one displays cost as a percentage of revenue, and the other, revenue as a multiple of cost. While the formula changes, the underlying relationship does not.

However, ACoS is only a good performance metric if you are comparing it against your break-even ACoS. That is why "20% is good" is meaningless if you don't know your product margin. That percentage alone tells you nothing.

How to Calculate Your Break-Even ACoS (The Only Benchmark That Matters for Your Product)

The Break-Even ACoS Formula

Break-Even ACoS = Contribution Margin ÷ Retail Price

Break-even ACoS is the ACoS at which your ad-attributed revenue equals your ad cost plus all your per-unit costs, so you make zero profit and zero loss.

To find it, take your retail price, minus your costs (COGS, FBA fees, referral fees and other per-unit costs), and then divide the contribution margin remaining by your retail price.

Break-even is at 38.75% ACoS for a $40 product with a $15.50 contribution margin, where ad spend has eaten up all of the margin. Anything below that is still profitable. Anything above that loses money on the sale.

Worked Example: A Supplement ASIN at $40 Retail

Let's take an example: a $40 supplement that has a $15.50 contribution margin, which is all that is left after all the costs.

If you spend $8 on ads, you will receive $7.50 of profit at 20% ACoS. At 40% ACoS, you are losing money for every $16 you spend, and the same goes for 50% ACoS - you end up losing money.

Now let’s say we have another product that only has an $8 contribution margin. That same 20% ACoS now eats away the majority of your profit. That is why generic benchmarks are insufficient.

20% ACoS could be wonderful on one product and unprofitable on another. The percentage alone doesn't matter; the relationship to break-even determines profitability.

How to Calculate Your Own Break-Even ACoS Right Now

This can be done within minutes. Collect your retail price, COGS, FBA fees (see Seller Central Reports), referral fees from Amazon’s fee schedule, and any inbound shipping or returns reserve costs you track.

You take those costs out of your retail price and you have your contribution margin. Divide that by your retail price and you have got your break-even ACoS.

If you are selling through Vendor Central, use your net wholesale price, not the retail price, because Amazon sets the retail price in that channel.

PRO TIP

Calculate break-even ACoS for each ASIN tier, not one number for the entire account. An $80 ASIN with a 45% margin has a much different break-even point than a $22 ASIN with a 25% margin. The blended target treats both the same so one of them is always being over- or under-optimised.

Why Your Commercial Objective Changes What “Good” Means

Before we set an ACoS target, every account at Olifant Digital begins with a discussion around a commercial objective. The same ASIN with the same unit economics can have five different correct targets, depending on what the brand wants to accomplish over the next 90 days.

Launch Velocity: When Above Break-Even Is Correct

For a new ASIN, the goal in the first 30 to 90 days is to build sales velocity, because Amazon calculates rank based on the sales rate. When an ASIN is profitable on ads, it continues to get reviews and it builds organic momentum, creating long-term organic value that the first-purchase ACoS never sees.

During this phase, you can accept a break-even ACoS of 30-80% as long as it is within the first 60 to 90 days. The real trouble begins when you never get out of this mode. The actual time frame is 60 to 90 days, and then your objective has to change.

Ekster is an example of that. They maintained an above break-even ACoS for the first 60 days to build velocity. Once they had established their organic rank, they moved on to Profit Maximisation which helped them generate $688,406 in annual profitability.

Profit Maximisation: When Well Below Break-Even Is the Target

Here is how to look at it. Your contribution margin is $15.50. You want to maintain a 10% net margin per sale ($4.00). That leaves you with $11.50 for ad spend. That is a target ACoS of 28.75% of your $40 retail price. You are protecting profit while organic ranking multiplies.

Ranking Defence and Market Share: The Middle Ground

Not all ASINs are launching or optimising profit. Many are in the middle ground, defending a position you have already earned or growing your share without paying too much for it.

These two targets are within a tolerance band close to break-even but they pull in opposite directions.

Ranking Defence: When You Have Rank to Protect

Once a brand has achieved its organic position, the job changes from building rank to maintaining it.

Competitors will try to erode your visibility by bidding on your best terms, so spend enough to be present on the keywords that matter without chasing every impression. Here the tolerance is break-even plus or minus 5%.

It is not about aggressive growth; it is about presence. You are defending the rank that already drives your organic sales at a cost that is just enough to be noticed but not at the high price you would pay in Launch Velocity mode.

If you pull back too much, you will lose placements that you spent months winning from competitors. Pushing too hard erodes the margin that makes the rank worth defending.

Market Share Capture

When the company is acquiring customers at scale and investing in growth rather than defending its margins, your tolerance is break-even plus 0-20%. Think of it as higher than Profit Maximisation but lower than Launch Velocity. You are buying customer acquisition, not ranking velocity.

Some campaigns are going to have a higher ACoS in this mode than some campaigns. That is the point. You are obsessing about new customer acquisition at the expense of short-term profit.

For example, Sponsored Brands Video campaigns might have a higher ACoS than your other channels, but if they are driving new customers at scale, then those new customers will pay for their acquisition cost over time through their lifetime value.

Stock Clearance: When ACoS Is Irrelevant

Once your inventory is near expiration, is discontinued, or becomes unsold stock on a shelf, the equation changes.

It is not even about making a sale anymore. The goal is to find the ACoS at which the inventory is cleared before storage and disposal costs reduce the revenue.

Tolerance here is break-even plus 50 to 150 percent. The ACoS is unprofitable per unit for a product with an 80% ACoS and a 38.75% break-even, but it will free up inventory that would otherwise cost $0.50-$1.50 per unit per month in storage fees, so the higher ACoS is the right financial decision.

In this situation, ACoS as a profitability metric is irrelevant. This is the only objective where this is the case. The real calculation is whether the cost of selling via ads is less than holding inventory.

PRO TIP

Before you set any ACoS goals, write down your commercial objective for every ASIN.

The biggest mistake in PPC is optimising for the wrong objective. This means being in Launch Velocity mode when you should have switched to Profit Maximisation, or running Profit Maximisation when you should be focusing on increasing market share.

When ACoS Is the Wrong Metric Entirely

The ACoS Blind Spot: What It Can’t See

ACoS is just ad spend divided by ad-attributed revenue. It is a metric that doesn’t count organic sales.

Imagine shifting budget from non-branded keywords (which build rank and create new customers) to branded exact match keywords (which intercept repeat buyers).

If organic revenue is flat and new customer acquisition is slowing, ACoS can look better. The dashboard can still look better, even when the real business is worse. ACoS is unable to see this decay, but TACoS, on the other hand, can.

TACoS: The Metric That Tells the Full Story

TACoS (Total Advertising Cost of Sales) is an ad spend-to-total revenue (including organic) ratio. It is the same concept as ACoS, but the denominator is all revenue, not just the ad-attributed revenue.

If an account spends $10,000 on ads and generates $35,000 in ad-attributed revenue and $20,000 in organic revenue, it will have a 28.6% ACoS but only an 18.2% TACoS.

Now, let’s say organic revenue drops to $10,000. ACoS remains at 28.6%, seeming unchanged. The TACoS is 22.2% and captures the decay that ACoS misses.

If the TACoS is declining over 6 to 12 months but total revenue is increasing, then the Amazon flywheel is working.

When your ad spend increases while your TACoS remains flat or rises, it indicates that your ads are concealing organic decay and failing to drive growth.

PRO TIP

Add your Campaign Manager ad spend plus your Seller Central Business Reports revenue to calculate the TACoS for your top 10 ASINs. If TACoS goes up for 2 months and ACoS stays flat, then look at organic rank decay before your next round of bids.

When to Switch from ACoS to TACoS as Your Primary Metric

There are instances where ACoS should be your primary metric. If the ASIN is new with no organic revenue, if you’re in Stock Clearance mode, or if you are purposely overspending to grab market share, keep ACoS at the storefront.

Switch to TACoS when you see it trending up for two months while ACoS is flat on the dashboard or when you switch into Profit Maximisation or Ranking Defence mode. Wait until ASIN has been live for 90+ days and organic rank is established. That divergence is a clear sign that organic revenue is declining.

At Olifant Digital, we look at TACoS per ASIN weekly, from day one. ACoS is left as a secondary check on campaign efficiency, not the primary health metric.

The Five ACoS Mistakes Olifant Digital Sees Most in Account Audits

Mistake 1: Targeting a generic benchmark without calculating your break-even.

Many brands try to hit a 20% ACoS target because they’ve heard this is a good number. The problem is that this number only works if your break-even is higher. 20% is great on a product with 38% break-even. If you have a product with an 18% margin, you are losing money. Your target must come from your own unit economics, not from industry benchmarks.

Mistake 2: Setting the same ACoS goal across all ASINs, regardless of their purpose. 25% sounds reasonable until you apply it to a new ASIN in Launch Velocity mode. It is not aggressive enough to create the rank velocity you need.

If you apply that same 25% to a mature ASIN that could be running Profit Maximisation at 15%, you will be losing out on a significant margin recovery. The targets should be aligned with ASIN maturity and commercial objectives.

Mistake 3: Cutting spend whenever your ACoS goes up in Q4 or after a CPC spike. Your ACoS will increase as competition increases and CPCs go up. This is the auction at work, not a sign that your strategy is broken.

If your conversion rate doesn’t change during the spike, then cutting spend will simply reduce revenue proportionally, without improving your per-unit economics. Check conversions still holding up before cutting.

Mistake 4: Evaluating individual campaigns based on blended account ACoS. A branded Sponsored Products campaign at 8% and SBV campaign at 42% combine into a comfortable 18%.

The branded campaign is cannibalising its own organic buyers. The SBV is bringing in new buyers at 55% new-to-brand but is being cut for pulling the blended number up. Compare the ACoS for each campaign to its goal.

Mistake 5: Celebrating growing ACoS with flat or rising TACoS. This is the most dangerous mistake on mature accounts. If you move the spend from non-branded acquisition to branded recapture, your ACoS will improve, but you will be capturing customers that are already coming and not new ones, which should be growing your base.

While the metrics will get better, the business will get worse. Once you include TACoS in every weekly review, you will catch this issue before it becomes a serious problem.

PRO TIP

If you get a blended-account ACoS report from an agency, ask them to break it down by campaign type: branded Sponsored Products, non-branded category keywords, and Sponsored Brands Video, all separately.

A healthy overall number driven by branded efficiency at the expense of acquisition looks fine on a blended basis and distinctly problematic when split.

How Olifant Digital Sets ACoS Targets Across 50+ Managed Accounts

We start every account with a discussion about commercial objectives before we set one ACoS target.

We will not give a number until we understand the 90 day goal of the brand: Launch Velocity, Ranking Defence, Profit Maximisation, Market Share Capture or Stock Clearance. That objective sets the tolerance and the tolerance sets the bid strategy.

Onsen Secret came to Olifant Digital after experiencing a plateau while optimising for ACoS. Their ACoS target was driving campaign decisions that were slowly degrading their organic ranking.

After we changed their metrics from ACoS to TACoS for ASIN reporting, we were able to see the real problem. We reorganised the account to the right commercial purpose and their profit tripled, adding $95,934 of revenue per month.

As competition in supplements increased, HakaLife responded by reducing spend to control the rising ACoS. That kept the metric in check but didn't do anything specific to solve the problem.

At Olifant Digital we took a different approach. We created strategic PPC differentiation, rebranded with premium positioning, shifted focus to high-intent keywords and integrated SEO with paid campaigns to create a seamless experience across both channels. This approach resulted in an 11% decrease in ACoS and $75,216 in monthly revenue.

Most of the accounts we have managed with TACoS-first reporting have achieved the same total revenue in year two with a lower median ACoS than in year one. The enhancement is largely due to organic rank compounding, which cuts down on paid traffic needed to maintain performance.

Get a free marketing plan from Olifant Digital. We will run the numbers for your break-even ACoS by ASIN, show you exactly where your targets are leaking margin and provide the plan to fix it. You will see exactly where your spending is misaligned and what it takes to turn it around.

Frequently Asked Questions

What is a good ACoS for Amazon Sponsored Products?

The secret to a good ACoS on Amazon is your product profitability, not industry standards. Your target is your break-even ACoS, the point where your ad spend is eating up all of your profit margin. For a product that has a 38% margin on a $40 price, that's 38.75%.

Any ACoS below that number makes money; any above it loses money per sale. So if someone says "20% is good," they are only right if your break-even is above 20%. Calculate your own break-even ACoS first, and work your target from there.

Is a lower ACoS always better on Amazon?

No, lower ACoS isn’t always better on Amazon.

If you can run 60 to 90 days above break-even during a launch, you create the organic ranking that will get you long-term free traffic, so a higher ACoS in that window isn’t a loss; it’s an investment.

A high ACoS may also be the right call in Stock Clearance mode where clearing inventory is more important than protecting margin on each sale.

Set each target based on what that specific ASIN is trying to achieve, not assuming lower is always better.

What is break-even ACoS on Amazon?

Break-even ACoS is the ACoS at which your ad spend has fully used your contribution margin, so you aren’t making or losing money on the sale.

To do this calculation you take your contribution margin and divide it by your retail price. Your contribution margin is your retail price minus COGS, FBA fees, referral fees, and any other per unit costs.

Anything below this threshold is profitable; anything above loses money on each sale.

What is the average ACoS on Amazon for each category?

Average ACoS can vary widely by Amazon category. Olifant Digital's data on 50+ accounts in the US, UK and EU, shows that median ranges vary across supplements, beauty, pet, accessories, home & kitchen, and sports & outdoors.

Category medians are a reference point, but your target should be break-even ACoS for your product.

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